[Elecraft] K3 Auto antenna switching

[Cady, Fred]

Hi Guy and all,
You could "kind of" do this with the DIGOUT1 signal from the ACC connector. It can be programmed OFF (floating, open-drain output, you need a pull up if you want a high) or ON (pulled down to ground). 
The Elecraft Owner's manual describes it on page 55 and here is what the KE7X K3 book says:
(Figure 7 16.) This output signal is a general-purpose, open-drain output that may be programmed (OFF = floating, ON = pulled down to ground) on a per-band and a per-antenna basis (if the KAT3 ATU is installed). For example, you might use this feature to turn on the PR6 six meter preamp only when the six meter band and the six meter antenna are selected. To program DIGOUT1, tune the K3 Main receiver to the desired band with the selected antenna and go to CONFIG:DIGOUT1 and set it to ON. The maximum sinking current is 250 mA and the maximum load voltage is 25 VDC.

So, "kind of" means you could program DIGOUT1 to be ON (pulled low) when you are on 80 and have ANT2 (for example) selected. For any other combination of band/ant DIGOUT1 would be floating (or pulled up). This would work if you are using an external band decoder to select antennas and you simply want to activate another switch or relay to switch in one of two 80 meter antennas.

Cheers and 73,
Fred KE7X


Fred Cady
fcady at ieee dot org
"The Elecraft K3: Design, Configuration, and Operation"
www.ke7x.com
 
> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net [mailto:elecraft-
> bounces at mailman.qth.net] On Behalf Of Guy Olinger K2AV
> Sent: Thursday, August 25, 2011 2:05 AM
> To: Oliver Dröse
> Cc: elecraft at mailman.qth.net; DBellW6AQ at aol.com; K6YR at aol.com
> Subject: Re: [Elecraft] K3 Auto antenna switching
> 
> I would really like an external signal that tells whether ANT1 or ANT2
> is
> selected.  Any way to do that?  73, Guy
> 
> On Wed, Aug 24, 2011 at 7:28 PM, Oliver Dröse <droese at necg.de> wrote:
> 
> > Hi Dave,
> >
> > unfortunately not, it's just one BCD code per band.
> >
> > 73, Olli - DH8BQA
> >
> >
> >
> > ----- Original Message -----
> > From: <DBellW6AQ at aol.com>
> > To: <elecraft at mailman.qth.net>
> > Cc: <K6YR at aol.com>
> > Sent: Wednesday, August 24, 2011 8:29 PM
> > Subject: [Elecraft] K3 Auto antenna switching
> >
> >
> > >I have two 80 meter  antennas.  Is it possible to program the band
> data
> > > output on the K3 for 80  meters # 1 and # 2?  I couldn't find an
> answer
> > to
> > > this
> > > in the  manual.
> > >
> > > 73,  Dave
> >
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